Pull Request Testing

• Describe testing already performed for these changes:
  

I created a test tag v3.4_test and used it to compile MET. With a few minor changes to MET, I was able to get all of the tests to run successfully. I also used this to run the METplus use case tests.

I also created test tag v3.4_test2 to double check that the METviewer build works because I had previously disabled it.

• Recommend testing for the reviewer(s) to perform, including the location of input datasets, and any additional instructions:
  

Review changes to Dockerfiles and README
After this PR is merged, we should create the v3.4 tag and remove any testing tags
Note that creating the new version of the METbaseimage does not mean we must switch MET to using it immediately.

• Do these changes include sufficient documentation updates, ensuring that no errors or warnings exist in the build of the documentation? [Yes]

• Do these changes include sufficient testing updates? [Yes]

• Will this PR result in changes to the test suite? [N/A]
  
  If yes, describe the new output and/or changes to the existing output:
  

• Please complete this pull request review by 2/21/2025.
  

Pull Request Checklist

See the METplus Workflow for details.

• Review the source issue metadata (required labels, projects, and milestone).
• Complete the PR definition above.
• Ensure the PR title matches the feature or bugfix branch name.
• Define the PR metadata, as permissions allow.
  Select: Reviewer(s)
  Select: Organization level software support Project or Repository level development cycle Project
  Select: Milestone as the version that will include these changes
• After submitting the PR, select the ⚙️ icon in the Development section of the right hand sidebar. Search for the issue that this PR will close and select it, if it is not already selected.
• After the PR is approved, merge your changes. If permissions do not allow this, request that the reviewer do the merge.
• Close the linked issue and delete your feature or bugfix branch from GitHub.
  …ENV and maintainer